Women in Technology

Article:		Networking and the BSD Sockets API
Subject:		Address in use
Date:		2002-12-28 20:29:13
From:		johnts
Great article, as usual. One thing I noticed, not really having to do with the code. When I run the server (and testing the client), I use Ctrl-C to quit the server. If I try to run the server again I get an error: "bind: Address already in use". Looks like the socket isn't being released right away. If I wait a bit, it will work again. I'm sure it's some TCP protocol issue, but thought I'd mention it.

Showing messages 1 through 2 of 2.

• Address in use
  2002-12-28 22:24:50  jasontm [View]
  
  
  you need to use setsockopt() to set the SO_REUSEADDR option. that way the socket won't stay bound to a port after your program has terminated. Unix holds onto them by default just in case your program launches in the near future. there's a delay that you remove by setting SO_REUSEADDR. :)
  
  use the mighty Google to find out more.. i'm too tired to launch into a tutorial. :P
  
  good luck..
• Address in use
  2002-12-29 17:44:43  johnts [View]
  
  
  Got it to work, using code from Beej's Guide page mentioned in another post - there was the exact description of the problem too. I added:
  
  int yes=1;
  if (setsockopt(listenfd,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) < 0) {
  perror( "setsockopt" );
  exit(1);
  }
  
  and I can start the server application right after stopping it without an error.